It took about 2 hours and you don't need to provide a credit card yet. It will be interesting to see what % of these trials convert to paying customers though.

Yahoo Answers and Vark.com don't always get the answer i need, for dev related questions stackoverflow does it a lot better, integration with niche websites might be a good idea, such as automotive portals.

Also don't underestimate localization, facebook really took off in mexico and spain once there was a spanish version.